var xmlHttp

//Method to add phone numbers dynamically.
function getCenters(value)
{ 
	var state = value;
	xmlHttp=GetXmlHttpObject()
	if (xmlHttp==null)
 	{
		alert ("Browser does not support HTTP Request")
		return
 	}
	var url="show_centers.php"
	url=url+"?state="+state //stores state
	url=url+"&sid="+Math.random() //stores random number to prevent caching.
	xmlHttp.onreadystatechange=stateChanged
	xmlHttp.open("GET",url,true)
	xmlHttp.send(null)
}


//Method to take care of the response text
function stateChanged() 
{ 
	if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
 	{ 
		document.getElementById("shopping").innerHTML=xmlHttp.responseText
 	}	 
}


//Method to create HTTP object.
function GetXmlHttpObject()
{
	var xmlHttp=null;
	try
 	{
 		// Firefox, Opera 8.0+, Safari
 		xmlHttp=new XMLHttpRequest();
 	}
	catch (e)
 	{
 		//Internet Explorer
 		try
  		{
  			xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
  		}
 		catch (e)
  		{
  			xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
  		}	
 	}	
	return xmlHttp;
}